Validation of the JSP page using Servlets

arvind368 · 11-02-2010, 04:30 PM

I have written a jsp page and I have done the client side validation using java script. But now i am asked to do the server side validation in servets . Please help with the code. I tried many ways , but i am unable to do that. Please rescue

register.jsp
<%--
Document : test
Created on : Nov 1, 2010, 3:41:06 PM
Author : db2admin
--%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">

<html>
<head>

<title> Registration </title>

<script type="text/javascript">

function checkWholeForm(theForm)
{
var why = "";

why += checkname(theForm.username, "user name");
why += checkPassword(theForm.password);
if ( theForm.password.value != theForm.password2.value )
{
why += "The two passwords do not match. Please enter the same password twice.\n";
}
why += checkname(theForm.firstname, "first name");
why += checkname(theForm.lastname, "last name");
why += checkEmail(theForm.email);
why += checkPhone(theForm.phno);

if (why != "")
{
alert(why);
return false;
}
return true;
}

function checkname(fld, name)
{
var val = fld.value;
if ( val.length < 3 || val.length > 10 )
{
fld.focus();
return "You must enter a " + name + " minimum 3 characters long.\n";
}

return "";
}

function checkPassword(fld)
{
var val = fld.value;
if ( val.length < 4 || val.length > 10 )
{
fld.focus();
return "You must enter a password that is atleast 5 characters long.\n";
}

return "";
}

function checkEmail(fld)
{
var val = fld.value;
//relational algebra standard for checking the emails
var emailFilter=/^[\w\-\'\.]+\@([\w\-\']+\.)+[a-z]{2,6}$/i;
if ( ! (emailFilter.test(val)) )
{
fld.focus();
return "Please enter a valid email address.\n";
}
return "";
}

function checkPhone(fld)
{
var val = fld.value;

// strip out ALL non-numeric characters
var ph = val.replace(/[^\d]/g, "");

if ( ph.length != 10 )
{
fld.focus();
return "The phone number must contain 10 digits.\n";
}

return "";
}
</script>

</head>

<body bgcolor="lightblue">
<form name="myform" method="post" action="SuccessfulRegistration.jsp" onsubmit="return checkWholeForm(this);">
<form name="myform" method="post" action="/servlet/validates"
<center>
<table>
<tr>
<center> <th><h1 style="font-family:arial;color:black;font-size:20px;"><i>eOnline Auction</i></h1></th></center>
</tr>
</table>
<br>
<br>
<br>
<br>
<table border="1" cellspacing="1" cellpadding="0" align="center" width=300>
<tr>
<td colspan="2" bgcolor="lightblue"><center><b>Registration Form</b></center></td>
</tr>
<tr>
<td>UserName</td>
<td><input type="text" size="20" name="username"></td>
</tr>
<tr>
<td>Password </td>
<td><input type="password" name="password"></td>
</tr>
<tr>
<td>Confirm password </td>
<td><input type="password" name="password2"></td>
</tr>
<tr>
<td> FirstName </td>
<td><input type="text" name="firstname"></td>
</tr>
<tr>
<td> LastName </td>
<td><input type="text" name="lastname"></td>
</tr>
<tr>
<td> Email </td>
<td><input type="text" name="email"></td>
</tr>
<tr>
<td> Address </td>
<td><input type="text" name="address"></td>
</tr>
<tr>
<td> Street </td>
<td><input type="text" name="street"></td>
</tr>
<tr>
<td> City </td>
<td><input type="text" name="city"></td>
</tr>
<tr>
<td> State </td>
<td><input type="text" name="state"></td>
</tr>
<tr>
<td> Zipcode </td>
<td><input type="text" name="zipcode"></td>
</tr>
<tr>
<td> Phonenumber </td>
<td><input type="text" name="phno"></td>
</tr>
<tr>
<td colspan ="2"><center><input type ="submit" value = "Register"></center></td>
</tr>
</table>
</center>
</form>

</body>
</html>

sujithpr · 11-03-2010, 05:33 PM

Server side validation is required because client side validation may be bypassed by disabling javascript . But you really mean to do server side validation in a seperate Servlet ?? You could do it in the same jsp page... Only one <form> tag is needed in your jsp page

BubikolRamios · 11-03-2010, 08:10 PM

will give you a short example how to do it:

say you have this div on top of everything that you already have, providing that action on your <form redirects to that same form:

Code:

<div>
<% 
      /*will pick up your street*/    
      String street = request.getParameter("street");
      if  street.equals("")
      {       
         out.print("error: street must be entered, data not submited !");
      }
      else
      {  
         //do saving to database here      
         out.print("data saved")
      }

%>
</div>

jvyrus · 03-25-2013, 08:52 AM

Quote:

Originally Posted by BubikolRamios

will give you a short example how to do it:

say you have this div on top of everything that you already have, providing that action on your <form redirects to that same form:

Code:

<div>
<% 
      /*will pick up your street*/    
      String street = request.getParameter("street");
      if  street.equals("")
      {       
         out.print("error: street must be entered, data not submited !");
      }
      else
      {  
         //do saving to database here      
         out.print("data saved")
      }

%>
</div>

The author has asked for the validation made in a servlet. Your code looks more like a scriplet (because the validation is done inside of the jsp), doesn't it?